SMART attribute: temperature value decoding

[Ericloewe]

I don't think there is a reference anywhere. It's just been assumed by solving for x. ;)

I've never seen anything other than "Hey, these add up to 150!".

Oh shit. I wasn't trolling you. I, for some stupid reason, really thought that the sum was 150. LOL. The joke's on me!

In all seriousness, that is supposed to be how you know the sum (at least, from the info I had). But apparently its not 150. Could it be 152?

WD Reds and Greens are definitely 150, from what I've seen. Other models are probably different. I think Samsung used 100.

 

[solarisguy]

FreeNAS 9.3.1, eight different WD60EFRX hard drives

Code:

ID# ATTRIBUTE_NAME          FLAG    VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
194 Temperature_Celsius     0x0022   115   113   000    Old_age   Always       -       37
194 Temperature_Celsius     0x0022   115   114   000    Old_age   Always       -       37
194 Temperature_Celsius     0x0022   118   114   000    Old_age   Always       -       34
194 Temperature_Celsius     0x0022   118   118   000    Old_age   Always       -       34
194 Temperature_Celsius     0x0022   119   104   000    Old_age   Always       -       33
194 Temperature_Celsius     0x0022   119   113   000    Old_age   Always       -       33
194 Temperature_Celsius     0x0022   119   114   000    Old_age   Always       -       33
194 Temperature_Celsius     0x0022   121   113   000    Old_age   Always       -       31

FreeNAS 9.2.1.9, two different WD40EFRX hard drives

Code:

ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
194 Temperature_Celsius     0x0022   120   112   000    Old_age   Always       -       32
194 Temperature_Celsius     0x0022   123   112   000    Old_age   Always       -       29

WD Blacks are rather out of scope for NAS, so let me just post that for the exemplars of models WD1502FAEX, WD2002FAEX and WD4003FZEX in our PCs, columns VALUE and RAW_VALUE also add to 152.

For WD Green WD15EADS I have, the sum is 150.

And then for a change, for WD Blue WD10JPVX (2.5" drives) I have, the sum is 157.

 

[Ericloewe]

So WD changed the sum from 150 to 152 relatively recently (for some messed-up reason)...

FreeNAS 9.2.1.9, two different WD40EFRX hard drives

How old are those 4TB Reds? My ~May 2014 3TB Reds still use 150, IIRC.

 

[solarisguy]

So WD changed the sum from 150 to 152 relatively recently (for some messed-up reason)...

How old are those 4TB Reds? My ~May 2014 3TB Reds still use 150, IIRC.

I am unable to look at the labels of those WD40EFRXs until sometime next month ;-) However, I have entered their serial numbers at the WD Warranty Status page, and by subtracting 3 years from their warranty expiration date, I have learned that both of them were manufactured on the 23rd of May 2014.

 

[Ericloewe]

So I just confirmed all my Reds use 150.

The two Greens in my workstation use 144 (manufactured sometime in 2010, probably).

 

[Ericloewe]

To further add to the mystery, all 7 of my new Reds use 150. WD30EFRX. Manufacturing dates are:

2015-08-28 x4
2015-10-30
2015-11-22 x2